Warp switch



Aus. 3, 1948 B. E. SHAW 2,446,307

WAR? SWITCH Filed sept. 11, 1944 6 5 48 39 /4 36 l im 4/ 42 L] i 44 e x/ l l /2 56 26 M @r5.4 34aso 7 56 33 f 1 52 64E 7U e4 o x. 1- Y .o se (e 66) /529 I Jg. 2

INVENTOR. 6 .Burfon E. Slaw- Patented Ang. 3, 1948 WARP SWITCH Burton E. Shaw, Lawrence,Vl Mass., assignor to Penn Electric Switch Co.. ('losherl. Ind., a corporation o! Iowa Application September 11, 1944, Serial No. 553,560

(Cl. 20D-122) 1 2 Claims. )Lv present invention relates to a warp switch which is so designed that it can be readily assembled as a so-called stack switch or one in which various leaf spring elements of the switch are supported in a stack of insulation spacers.

One object of the invention is to provide a warp switch having stationary and movable contacts and an actuating blade for the movable contacts f with a toggle spring connection between the actuating blade and the movable contact.

Another object is to provide means to automatically move the actuating blade comprising a -bimetal element adjacent which an electrical heater is positioned, the bimetal element and the heater being supported in the stack of insulation spacers with the bimetal element assisting inthe support oi the heater.

Still another object is to provide trip-free resetting mechanism including a reset button .which is slidably mounted in a support that is also supported in the stack of insulation spacers.

A further object is to provide a pair of adjusting means for the switch, particularly for the actuating blade thereof to determine the position oi' the toggle spring at one limit of its movement,

and to engage the switch blade at one point to determine its position during resetting operations,

the adjustment means being supported on a blade that is also in turn supported in the insulation spacers.

With these and other objects in view, my inven tion consists in the construction, arrangement and combination ci the various parts ci my device whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawings, wherein; i

Figure 1 is a side elevation of my warp switch showing the switch in set position.

Figure 2 is an end elevation thereof.

Figure 3 is a view similar to Figure 1 with the switch tripped by warpage oi.' the bimetal element caused by energization oi' its heater.

Figure 4 is a view similar to Figure 1 showing the resetting position of the switch blades.

Figures 5 and 6 are vertical sectional .views on the lines 5-5 and 6 6 respectively of Figure l, and

Figure Z is an enlarged sectional View on the line l-'l oi Figure l. l

On the accompanying drawings I have used the reference numeral l0 to indicate a switch blade and I2 an actuating blade. The switch blade I0 carries a movable contact I4 for engagement with a stationary contact i8. The contact It is car- 2 ried by a supporting blade i8 which is somewhat resilient to prevent bouncing of the contacts when they close as disclosed in the copending application of Leland B. Wagner, Serial No. 514,483, filed December 16, 1943, which application has become abandoned.

My warp switch further includes a toggle spring 20 having its ends mounted on projections '22 and 2% of the switch blade i0 and the actuating blade I2 respectively (see Fig. 5). The switch blade has an opening 26 cut therein for the purpose of permitting clearance for the spring 2li.

A bimetal element 28 of blade-like character is also provided having its upper end bent as at Sil. A pair of heater supporting clips32 are provided, to the ends of which an electric heater 3d (formed of a coil of resistance wire) are con- A reset button 3B is provided having a shank" 38 slidable through a supporting blade 4l) and an ear l2 thereof. The reset button is biased toward the leit in Figure l by a. spring ii interposed between the ear42 and a cotter pin fit through the shank 3B. The shank 38 has a reduced end i3 iitting loosely through an opening 5G in the switch blade i@ and adapted to coact with the Contact blade i8 during resetting operations, as shown in Figure e.

l provide another supporting blade bbhavlng adjusting screws bil for coaction with the actuating blade l2 as shown in Figure 3, and a iJ-shaped clip @il (see Fig. 7) which is adapted to adjust the position of the switch blade as in Figure 4 by contact therewith. The clip 56 is held away from the blade 52 by a leaf spring 58 and may be acljusted toward it by an adjusting screws@ whereby the ears of the clip may be adjusted relative to the rigid blade 52.

The switch blade lli, the actuating blade l2, the supporting blade i8, the bimetal element 25, the heater supporting clips 32, the supporting blade 4% and the supporting blade 52 are all supported in a stack of insulation spacers t2 with the exception of the blades l0 and l2 which are next to eachother. The various blades to which circuit connectlons are made are provided with terminal ears 64 to which circuit wires may be soldered.

The stack of blades and insulation spacers are clamped between brackets 65 and 68 by a pair of screws l0, the screws extending rotatably through the bracket GB, through insulation sleeves 'l2 in the holes of the blades and spacers, and threaded into the bracket 6B.

Practical operation In the operation of my warp switch, when it set as in Figure 1, current flows across the contacts I l and It. When current of suiiiclent magnitude ows through the heater 34, it will be i heated and Warp the bimetal element to the position shown in Figure 3 which causes the toggle spring to snap to the opposite position for separating the contacts. The position of the toggle spring is determined by adjustment of the screw 54 whereby the characteristic of the snapto-open position may be changed as desired.

After the heater 3d has cooled, the switch mair be reset as in Figure 4 by pushing on the button 36 which changes the position of the toggle spring and causes the switch to snap toward closed position. As long as the button 36 is held in, the reduced portion it thereof holds the supporting blade H in such a position that the contacts are disengaged thereby and provide trip-free opern ation thus preventing the holding of the contacts closed when the bimetal element 2d is still warped to a position requiring the contacts to be open. The resetting position of the switch blade i@ may be adjusted by means of. the screw t0 so that the spacing of the .contacts from each other while the reset button is held in, may be varied as desired.

A warp switch of the character disclosed has its most general application as a safety switch in connection with oil and gas burner systems. When a burner operation is initiated there may be an initial failure of combustion or a failure of combustion subsequent to successful establishment thereof. If combustion is successfully l established within the timing period of the heater,

the heater is deenergized-and therefore the warp switch does not trip. On the other hand, if there is initial or subsequent failure, this results in energization of the heater long enough so as to operate the warp switch to the position of Figure 3.

From the foregoing specification it will e obvious that I have provided a warp switch, the

, elements of which are inexpensively fabricated and assembled together with the insulation spacers d2 between the brackets @t and Gti to form the complete switch. The assembling operations are not at all complicated and after the parts are assembled the switch may betested and readily adjusted `for proper operation by the two screws 5d and @0.

4 7 some changes may be made in the construcf tion and arrangement ine the parts of my warp switch within the scope of the appended claims without departing from the real spirit and purpose of my invention. I therefore intend to cover ably included within their scope.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a warp'switch, a switch blade, amovable y contact carried thereby, a stationary contact for coaction with said movable contact, an actuating blade, a toggle spring connection between said actuating blade and said switch blade, a bimetal element, a heater therefor, and heater supporting clips for said heater, said bimetal element cocating with said actuating blade to actuate the same and thereby operate said switch blade through said toggle spring, said blades, said bimetal element and said clips being supported in a stack of insulation spacers, and said heater having its ends connected to said clips and its center portion connected with and supported by said bimetal element. s

2. In a'warp switch, a switch blade, a movable contact carried thereby, a stationary contact for coaction therewith, an actuating blade, a toggle spring connection between said actuating blade and said switch blade, a bimetal element, a heater therefor, supporting clips for said heater, said heater being supportedv by said. bimetal element and said supporting clips. said bimetal element coacting with said actuating blade to actuate the same and thereby operate said switch blade through said toggle spring, said blades, said bimetal element and said supporting clips for said heater being supported in a stack of insulation spacers, and means for resetting said warp switch.

BURTON E. SHAW.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,763,006 Murphy Jun@ l0, 1930 2,135,864 Weber Nov. 8, 1938 2,189,996 Riche Feb. 13, '1.940 2,211,245 Shaw Aug. 13; 194.0 2,330,506 Matthias Sept. 28, 1913 2,394,121 Ulanet Feb. 5, i946 

